Yarn supply device group

ABSTRACT

The invention relates to a yarn supply device group for attaching to a textile machine, in particular a ring knitting machine with electrically controllable switching and actuating devices in every supply device which are connected in a signal-transmitting circuit by a bunch of lines common to all supply devices to a central control mechanism. Previously, every supply device in the group had to be &#34;marked&#34; manually prior to the start of operation. In addition, a bunch of lines with large dimensions was necessary, since each supply device needed at least one separate line. In the invention, manual &#34;marking&#34; is not needed, since in each supply device an electronic switching arrangement which contains a writable and readable memory is associated with the switching or actuating devices, can be supplied with an individual address from the central control mechanism, and after having been supplied the address can be controlled addresslike, and for connection of the supply device to the central control mechanism a small-dimensioned bunch of lines can be provided since the switching arrangements of all supply devices are connected in the same manner to the bunch of lines.

FIELD OF THE INVENTION

The invention relates to a yarn supply device group for attaching to atextile machine, in particular a ring knitting machine with electricallycontrollable switching or actuating elements in every supply devicewhich are connected in a signal-transmitting circuit to a centralcontrol mechanism by a bunch of lines common to all devices.

BACKGROUND OF THE INVENTION

From European Patent Application No. 801 067 19 (corresponds to U.S.Pat. No. 4,386,508) is known to construct a bunch of lines as a flatmulti-conductor cable, in which at least as many conductors or wires arearranged side-by-side as there are supply devices in the supply devicegroup. Since for example fourteen or more supply devices can beassociated with one knitting machine, and since for every supply device,if necessary, several lines or wires in the bunch of lines are needed,the bunch of lines has considerable dimensions and is difficult tostore, due to extremely cramped space conditions. Furthermore, thefunction-correct connection and "marking" of the supply devices, priorto the first use of the textile machine or after rearrangement or theconnecting or "marking" of one or several exchanged supply devices, isextremely expensive. It is namely necessary that an operator manuallyand suitably position one or several contact pins inside of the supplydevice, so that the suitable circuit connections between the switchingor actuating elements and the central control mechanism are formed. Thismanual "marking" in addition is time-consuming and causes an undesirablylong stand-still time for the textile machine.

The basis of the invention is the technical problem of how to constructa yarn supply device group of the above-identified type so that thestructural provisions for connecting the supply devices to the centralcontrol mechanism are considerably reduced and so that mainly theadjusting or "marking" of the supply devices in the supply device groupis simplified and can be carried out more quickly.

SUMMARY OF THE INVENTION

The set problem is solved inventively by providing a yarn supply devicegroup in which each supply device has an electronic switchingarrangement which contains a writable and readable memory associatedwith the switching or actuating devices, which can be supplied with aunique address from the central control mechanism and which, afterhaving been supplied with the address, can be controlled by beingaddressed, wherein the switching arrangements of all supply devices areconnected in the same manner to the bunch of lines.

In this construction, due to the electronic switching arrangement, towhich can be fed an address from the central control mechanism, a manualmarking of each supply device is not necessary. As soon as operationstarts, the central control mechanism supplies an address to eachelectronic switching arrangement, under which address then duringoperation each supply device can be controlled individually. This meansthat the supply devices of the group need only be fixed mechanicallywithout "marking" and that then the textile machine is immediately readyfor operation. A further, important advantage consists in the bunch oflines containing only a small number of lines, since all supply devicesare connected in the same manner to the same lines, so that theconnection can be carried out relatively simply and the structural partsand the space for storing the bunch of lines is considerably reduced,because it is no longer necessary to select for each supply device aspecific line or lines. The bunch of lines can be integratedstructurally without any difficulties into the supply device group orthe storing of the group, so that little space is needed for the bunchof lines and it no longer hangs around interferingly between theindividual supply devices and the central control mechanism. Thestandstill times of the textile machine, prior to starting operation,after breakdowns in operation, after change-over operations duringwhich, if necessary, individual supply devices of the group wereexchanged, after repair or exchange operations, and during methodchanges, can be shortened drastically through this.

Particularly advantageous is thereby an embodiment in which the bunch oflines includes a line which is designated for carrying the addresses andis connected to the switching arrangements in series, while theswitching arrangements are connected in parallel to the other lines ofthe bunch of lines. During the first adjusting of the supply devices ofthe group, just as little care must be taken for connecting theindividual cables to the switching arrangement as after exchanging thepositions of supply devices of the group, since the exchanged supplydevices assume the same positions with respect to the lines of the bunchof lines as the supply devices which were provided earlier at suchplaces. With the series connection in one line of the bundle of lines,the assigning of addresses to the individual supply devices can becarried out according to a relay circuit, so that even after anexchange, supply devices of the group can be controlled againindividually from the central control mechanism without having to be"marked" again.

A further advantageous embodiment of the invention provides amicroprocessor in each switching arrangement Microprocessors are simple,premanufactured and inexpensive electronic structural elements which canbe programmed selectively for respective applications. They arecommercially available and require, for example as chips, extremelylittle space for storage. It would, of course, be conceivable to use inplace of a microprocessor a custom electronic switching arrangement; butthis would be substantially more expensive than a microprocessor, whichis usable for many different purposes and is programmed in view of theexpected, known steps.

Since in such a textile machine under certain operating conditions, forexample during starting up of the normal operating program or duringstopping of a specific quality of goods, the supply devices of the groupare supposed to operate only according to a simplified program, or sinceit may be necessary to leave one or some of all existing supply devicespassive, it is advantageous if each switching arrangement has a manuallyoperable switch with which its microprocessor can be separated from thelines of the bunch of lines. Since during switching off of thisswitching arrangement the current flow in the one line of the bunch oflines in which the switching arrangements are arranged in seriesremains, the assigning of the addresses to the remaining supply devicesand their individual control through the switching off of the switchingarrangement is not influenced.

A further, advantageous embodiment involves the microprocessor of eachswitching arrangement having a read only memory for at least one fixedcontrol program. Fixed programs can be stored in such read only memoryor the read only memories and can be read either under control of thecentral control mechanism or by operations in the respective supplydevice itself. In this construction, a universal usability of the supplydevices is achieved.

Furthermore, also advantageous is an embodiment in which the centralcontrol unit contains a microprocessor having an input connected to atleast one signal producing control element which provides, for example,the operating clocks, operating position, operating speed and the likeof the textile machine. In this manner, not only a structuralsimplification and universal usability of the central control mechanismfor various operating methods is made possible, but it is also assuredthat the central control mechanism and the supply devices in the groupcan be operated in strict and desired dependence from the operatingclocks or the operating speed during each operating phase. Due to thiscontrol of the central control mechanism, it and also the supply devicesremain independent from fluctuations in the operating clock or theoperating speed during each operating phase. It is thereby alsoadvantageous that the coupling between the textile machine and thecentral control mechanism occurs also in an electrical or electronicmanner which is not susceptible to breakdowns and needs littleinstallation space.

A further, advantageous thought involves the microprocessor of thecentral control unit being able to store and selectively recall at leastone fixed program for effecting a uniform control of all switchingarrangements. Here again a central control mechanism right from thestart receives the possibility to adjust and uniformly control thesupply devices during specific steps which differ from the normalworking operation according to these respective conditions.

A further, advantageous measure which results in a simplification of theoperation involves the provision in each switching arrangement of adevice for detecting, coding and transmitting the occurrence of an errorto the central control unit, the central control unit having an errorindicator. This additional device in every supply device fulfills thepurpose to localize errors which occur in every supply device and toanalyze same and make them recognizable by the central controlmechanism, so that it can stop the textile machine and at the same timeannounce the type of error.

It has thereby proven advantageous if each supply device has an errorindicator controlled by its microprocessor, since then in the region ofthe central control mechanism the type of error can be recognized, andin addition it can indicate in which supply device the error occurred.The search for the error and the correction of the error issubstantially simplified through this.

An embodiment which is particularly protected against damage from dirtand other outside influences is one in which each yarn supply device hasa housing which contains its switching arrangement. Especially duringuse of a microprocessor, the space which is available in common supplydevices is very sufficient for storing the switching arrangement.

Finally, a further advantageous embodiment is one in which the centralcontrol unit and the yarn supply device are all supported on an annularcarrier. The bunch of lines can hereby be located in the annularcarrier, on which is also secured the central control mechanism. Thus,interfering and space-consuming cable connections between the centralcontrol mechanism and the supply devices are not needed. As is knownalready, during fastening of the supply devices on the annular carrier,the respective correct connections between the control mechanism and theswitching arrangements can be created.

A particularly advantageous use of the subject matter of the inventionresults in connection with an electronically or electrically controlledring knitting machine, in which the individual ring devices arecontrolled centrally by a so-called pattern computer. Such patterncomputer can be connected to the central control unit for the supplydevices with the interpositioning of an interface switching circuit,which causes the central control unit and also the microprocessors inthe supply devices to be controllable in parallel with the signals fromthe pattern computer which are also intended for the ring devices and,for example, indicate the respective colors or a color change. Thus, thestep which is necessary during the mechanical control of the ringdevices is not needed in the individual supply devices, with which stepthe yarn-guiding arms which are on the output side are lifted into acentral position, from which then a signal is formed by a yarn-guidingarm which is moved under the yarn tension from the side of the ringdevice, which signal indicates to the microprocessor in the supplydevice which color must now be continuously delivered. This step occurssensibly during each machine phase, even if no yarn change takes place.During the electronic control of the ring devices, through the saving ofthis step, a simplification is achieved, since the microprocessors inthe supply devices are utilized for fewer switching operations and alsothe central control unit has to carry out fewer switching operations,since the microprocessors in the supply devices can each be controlleddirectly with the order for a color change and for the respective color.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in connection with one exemplaryembodiment which is illustrated in the drawings, in which:

FIG. 1 is a partially cross-sectional side view of an exemplaryembodiment of a supply device;

FIG. 2 is a cross-sectional view taken along the line II--II of FIG. 1;

FIG. 3 is a partially cross-sectional rear view of the exemplaryembodiment of FIG. 1;

FIG. 4 is a block diagram of the electronic circuit in each supplydevice;

FIG. 5 is a block diagram of an electronic control unit which isutilized for controlling all supply devices of FIG. 1;

FIG. 6 is a schematic top view of a fourteen-device ring knittingmachine;

FIG. 7 is a timing diagram for the control of the supply devices.

DETAILED DESCRIPTION

A supply device for positive yarn delivery has a housing 1 with a clampportion 3 which can be fastened to a support ring 2 of the knittingmachine, namely with a screw 4. The support ring 2 carries above theknitting systems a number of such supply devices which corresponds tothe system count of the machine (FIG. 6).

The clamp portion 3 extends with a projection 3A into the housing 1 anddivides same into chambers 1A or 1B. The projection 3A extends in FIG. 1beyond the housing 1 and forms a support plate 3B for a vertical,nonrotatable axle 3C. Several (here four) yarn-feeding wheels 5A, 5B,5C, 5D are supported rotatably on the axle 3C with bearings (notillustrated). A tape 6A, 6B, 6C or 6D which is driven in synchronismwith the knitting machine runs over each wheel. The number ofyarn-feeding wheels corresponds with the number of preferablydifferent-colored yarns for the associated ring device.

In the housing 1, at the same level as the wheels 5A, 5B, 5C and 5D,there are supported four times two =eight yarn-guiding arms 7A in, 7Aout, 7B in, 7B out, 7C in, 7C out, 7D in, 7D out on axles which extendhorizontally into the housing 1.

All arms 7A in, 7B in, 7C in and 7D in for the incoming yarns aresupported identically, as are the arms 7A out, 7B out, 7C out and 7D outfor the outgoing yarns, so that only the arms 7A in and 7A out will bedescribed hereinafter.

An armature plate 8A is supported on the axle of the arm 7A in, whichplate cooperates with an "engagement" electromagnet 9A which, whenactuated, swings the armature plate 8A against the action of a spring10A in a clockwise direction (upward in FIG. 1). When the electromagnet9A is no longer actuated, the spring moves the arm 7A in acounterclockwise direction (downward in FIG. 1) toward a stop 11A.

A support plate 12A (see 12D in FIG. 1) for a draw spring 13A (see 13Din FIG. 1) is supported on the axle of the arm 7A out, the other end ofwhich draw spring is supported on a support plate 14A (see 14D inFIG. 1) which in turn is secured on the housing 1 by means of a screw15A. The draw spring 13 pulls the arm 7A out in a counterclockwisedirection (namely upward in FIG. 1). On the axle of the arm 7A out,there is fastened an essentially L-shaped plate 16A with a stop surface17A for limiting counterclockwise movement of the arm 7A out, anactuation surface 18A and a contact plate 19A. A contact cam 20A issecured on the axle of the arm 7A. The contact plate 19A of the L-shapedplate 16A cooperates with a stationary contact plate 21A on a projection22A. A contact tongue 24A is secured by means of a screw 23A on theprojection 22A, which extends vertically downwardly and cooperates withthe contact cam 20A. The operating surfaces 18A, 18B, 18C and 18D of theother arms 8B out, 8C out or 8D out cooperate with further operatingsurfaces 25A, 25B, 25C or 25D of a vertical draw bar 26 which is securedon an armature (not illustrated in FIGS. 1 to 3) of a liftingelectromagnet 27. When the electromagnet 27 is actuated, the draw bar 26is moved upwardly a small distance, which causes the arms 7A out, 7Bout, 7C out to be swung in a counterclockwise direction into a centerposition, since the draw bar 26 with its surfaces 25A, 25B, 25C or 25Dengages the plates 16A, 16B, 16C or 16D on the axles of the arms 7A out,7B out, 7C out or 7D out. The contact cams 20 do not yet cooperate inthe center position of the arms with the contact tongues 24.

When the electromagnet 27 is no longer actuated, the draw bar 26 dropsback into its rest position, due to its weight and the weight of thearmature (FIG. 1).

The contact plates 21A, 21B, 21C and 21D and the contact tongues 24A,24B, 24C and 24D are connected by (not illustrated) electrical lines toa contact pin 28S (FIG. 1) of an electrical circuit board 28 (FIG. 2)which contains a switching arrangement in the form of a microprocessorwhich will be described hereinafter.

Further contact pins of the electrical circuit board 28 are connectedwith contact sockets 29 or 30 to further lines (not illustrated), whichcontact sockets 29 or 30 are provided here on opposite sides of thehousing (see FIG. 2). To each socket there is connected a flat cablewith preferably six conductors, which is utilized as a so-called "buscable" in order to feed control signals and a supply current to anelectronic central control unit CU (FIGS. 5 and 6) and to receivesignals from same, which is preferably secured on the support ring 2 andcontains a microprocessor. In place of the sockets 29, 30 it would alsobe possible to provide a contact-pin arrangement in the chamber 1b, withwhich then the conductors of the bus cable can be connected at thesupport ring 2.

Furthermore, plates 31 and 32 are secured on the housing 1, which platesextend outwardly and respectively have four fixed ceramic eyelets 33A,33B, 33C and 33D for guiding the yarns FA, FB, FC or FD and four fixedceramic eyelets 34A, 34B, 34C and 34D for guiding the yarns FA', FB',FC' or FD'. The yarns are positively guided by the wheels 5A, 5B, 5C or5D and the tapes 6A, 6B, 6C or 6D and leave the supply device downwardlyto a ring device, in which they are detected by fingers and are guidedon downwardly to the needles of the knitting machine. Between theeyelets 33A, 33B, 33C or 33D and the wheels 5A, 5B, 5C or 5D, theincoming yarns FA, FB, FC or FD run through ceramic eyelets 35A, 35B,35C or 35D on the free ends of the arms 7A in, 7B in, 7C in or 7D in.

The outgoing yarns FA', FB', FC' or FD' run through ceramic eyelets 36A,36B, 36C or 36D at the free ends of the arms 7A out, 7B out, 7C out or7D out, after they have passed through the eyelets 34A, 34B, 34C or 34D.

A lamp 37 in FIG. 1 provides a visual error indication, while a manualswitch 38 is designated for switching off the microprocessor in thesupply device.

FIG. 4 illustrates the microprocessor FMP (supply devicemicroprocessor), for example a so-called "one-chip" microprocessor, in asupply device FU_(n) (where n lies in this case between one andfourteen). The microprocessor is supplied with a voltage of 5 V (directvoltage) by a voltage threshold, which from a 24 V voltage supply letsthrough only 5 V for other switching arrangements in the supply device,and is connected by the "bus cable" in the form of the flat cable withsix conductors to identical microprocessors of the two adjacent supplydevices. The first supply device FU1 (FIG. 6) and the last supply deviceFU14 of the group are connected to the control unit CU, which isillustrated in FIG. 5 and FIG. 6. The "bus cable" contains a line forthe voltage supply and five signal lines for controlling themicroprocessor in every supply device or for monitoring the system withrespect to occurring errors of various types. These cables areidentified in FIG. 4 with: RESET, STOP SIGNAL, CLOCK, DATA, and RELAY.The functions which can be effected therewith will be described later.It is important that the microprocessors FMP are connected in series inthe cable RELAY, while in the remaining cables they are connected inparallel with one another.

The microprocessor FMP is connected in the supply device to the "trig"contacts 19A/21A, 19B/21B, 19C/21C and 19D/21D and to the "stop"contacts 20A/24A, 20B/24B, 20C/24C and 20D/24D.

The microprocessor FMP controls, through a driving circuit which issupplied with 24 V, the electromagnets 9A, 9B, 9C and 9D, the liftingmagnet 27 and the lamp 37. The manual switch 38 can switch off allfunctions in the microprocessor FMP, with the exception of thetransmission of the RELAY signal. When the switch is in its "off"position, the microprocessor FMP does not take notice of any otherinformation on the "bus cable".

The central control unit CU in FIG. 5 consists in reality of amicroprocessor CMP (central microprocessor), which is also a "one-chip"microprocessor supplied with plus 5 V direct voltage.

For synchronizing the operation of the microprocessor CMP in the centralunit CU with the operation of the ring knitting machine, a positionsensor SYNC is provided (for example a Reed switch) which cooperateswith the drive shaft of the rib cylinder of the knitting machine inorder to feed one pulse per revolution of the knitting machine to themicroprocessor. A for example photoelectrical sensor FREQ cooperateswith a toothed disk on the drive shaft of the knitting machine in orderto feed a pulse train having a frequency which corresponds to themomentary speed of the knitting machine to the microprocessor CMP in thecontrol unit CU.

The microprocessor CMP is connected to a display DISPLAY in the controlunit CU which indicates only two characters which provide a visual,coded indication of the type of an occurring error, whereby for examplea yarn breakage is indicated with the code "1 1" and an error in thesignal transmission with the code "2 2".

The microprocessor CMP in the control unit CU is connected, forcommunicating with the respective microprocessors FMP in every supplydevice of the system, according to the invention to the "six wire buscable" which is mentioned in connection with FIG. 4.

T1, T2, T3 and T4 (FIG. 5) identify four manual switch buttons in thearea of the central control unit, the function of which will bedescribed hereinafter.

FIG. 6 illustrates the supply devices FU1 to FU14 and the control unitCU on the support ring 2 of the knitting machine. It can thereby berecognized how the feeding tapes 6A, 6B, 6C and 6D are driven by a shaft39 through a roller 40 with a variable diameter (for changing the tapespeed) and a stretching device 41 with a drive belt 42.

The described exemplary embodiment operates as follows.

When the power supply for the ring knitting machine is switched on, eachsupply device FU1 . . . FU_(n) . . . FU_(m) in the group receives aspecific address from the control unit CU, whereby m equals the totalnumber of supply devices and is fourteen. In other words, each supplydevice receives a unique number which it keeps until the next addressingoperation takes place, namely until the ring knitting machine isswitched on the next time.

The addressing is carried out by the control unit CU, which sends out asignal, for example a binary zero (equals a low potential) on the RELAYline when it starts to send pulse trains on the CLOCK line. The signalon the RELAY line enters the microprocessor FMP1 of the supply devicenumber 1 (FU1), whereby same is programmed so that it starts to countand stores in an internal memory the number of clock pulses whichoccurred up to this point in time on the CLOCK line, namely in this case"one". The signal on the RELAY line continues from the RELAY output ofthe microprocessor FMP1 in the supply device FU1 to the RELAY input ofthe microprocessor FMP2 in the supply device FU2, which upon receipt ofthe RELAY signal reads that so far two pulses occurred on the CLOCKline, whereby this number is stored in its internal memory. The RELAYsignal continues to run from supply device to supply device until it haspassed the last supply device FU_(m) of the group, the microprocessorFMP_(m) of which reads or counts that m pulses have occurred on theCLOCK line, so that this supply device receives the address "m" (forexample "fourteen").

The important advantage in this addressing operation or "marking" of thesupply devices lies in the supply devices, if this should be desirablefor one reason or another, being able to be moved or exchanged freelywithin the system. The position of each supply device in the group canbe changed freely, or alternatively one supply device can be replacedwith a new supply device without a "marking" being carried out manually,as is necessary in the known system according to European PatentApplication No. 80106719.9. In the known system, the supply devices mustbe "marked", in that the position of a specific contact pin must beadjusted to a specific wire in the flat multi-conductor cable.

The automatic addressing operation in the inventive system eliminatesalso the up-to-now existing disadvantage of the first-time "marking" byhand prior to the first operation of the ring knitting machine.

In the described exemplary embodiment, knitting station No. 12, namelysupply device FU12, is for example viewed now. At a certain moment, theneedles of the ring knitting machine work with the yarn FD', which isfed positively by the uppermost yarn feeding wheel 5D by means of theyarn feeding tape 6D. Just then a change to the yarn FA' takes place inthe associated ring device.

Immediately prior to such moment, the control unit CU, which operates insynchronism with the knitting machine, sends out an addressing orcalling signal in the form of a 6-bit word (whereby the highest possibleaddress is sixty-four), in this case the number "twelve", namely on theDATA line. The microprocessors in all supply devices FU1 to FU14 receivethe information on the DATA line each time they receive a pulse on theCLOCK line. They are programmed so that they compare the calling signal,which was sent out by the central control unit, with the address whichis stored in their internal memory and

(1) if the comparison is positive, respond to the calling signal bysending back a receipt signal to the central control unit CU on the STOPsignal line, whereas,

(2) if the comparison is negative, they do not respond to the callingsignal.

Upon receiving back such a receipt signal, the central control unit CUsends out one or several orders or order signals on the DATA line,whereby each order signal is a 4-bit word (the possible total number oforders is sixteen), but only the microprocessor FMP12, which was called,is enabled to read or to receive the order signal or signals which occuron the DATA line. If the central unit does not receive the receiptsignal promptly after sending out the addressing or calling signal, itproduces in accordance with its program an error indication or a STOPsignal for the knitting machine.

At this very moment, the order or the instruction to the microprocessorin the supply device FU12 is to "disengage the positive feed", (orderI). During receipt of the order I, the microprocessor FMP of each supplydevice carries out three different operations, namely:

(1) to switch off the current to all "engagement" electromagnets 9A, 9B,9C and 9D in the supply device;

(2) to switch on the current to the "lifting" magnet 27;

(3) to switch off the stop function of all arms 7A out, 7B out, 7C outand 7D out, namely the co-acting contact cams 20A, 20B, 20C and 20D andthe contact tongues 24A, 24B, 24C and 24D.

Through the operation (1), the "working" arm 7D in is swung inward in acounterclockwise direction, namely downwardly in FIG. 1, which causesthe yarn FD on the feeding wheel 5D to be pulled out from under thefeeding tape 6D, and the positive feeding is stopped.

Through the operation (2), the draw bar 26 is moved, which causes the"working" arm 7D out, and also the other arms 7A out, 7B out or 7C out,which possibly in this moment are in their lower position, for exampledue to the elasticity of the yarns, to be rotated a distance in acounterclockwise direction, namely in FIG. 1 upwardly, into apredetermined central position. The contacts 20, 24, however, are notclosed.

The central control unit CU now again sends the address signal "twelve"on the DATA line. The microprocessor in the supply device FU12 operatesby sending back a receipt signal to the central control unit on the STOPSIGNAL cable, whereupon the control unit CU sends out a new order II onthe DATA line, which again is only carried out by the supply deviceFU12. The order II reads "change the color". The microprocessor FMP ofeach supply device is programmed to proceed upon receipt of the order IIas follows:

(4) all arms 7A out, 7B out, 7C out, 7D out are released, since thelifting magnet 27 is de-energized; and

(5) the current is switched on to the "engagement" electromagnet 9A, 9B,9C or 9D whose associated arm 7A out, 7B out, 7C out or 7D out has beenmoved by a yarn FA', FB', FC' or FD' into a so-called "trig position",whereby such yarn must now be processed and is therefore tensioned. The"trig-position" corresponds with the contact position of the plates19A/21A, 19B/21B, 19C/21C or 19D/21D, in this case the contact plates19A/21A, as is illustrated in FIG. 1.

Through this operation, the corresponding arm 7A in, 7B in, 7C in or 7Din, in the present case 7A, moves the yarn FA, FB, FC or FD, in thepresent case FA, upwardly into a position under the corresponding yarnfeeding tape on the feeding wheel so that it is fed positively, namelywith a constant speed in synchronism with the ring knitting machine.

An internal program routine runs thereby in the microprocessor FMP ofthe supply device in order to ensure that the correct yarn is fedpositively, regardless of the fact that disturbances can occur in thesupply device, for example due to an increased tension due to theelasticity of the just stopped yarn. It may also happen that two outputarms are moved into the "trig position" and each produce a trig signal.If then the microprocessor FMP would not have any internal programroutine (as described hereinafter), two yarns would be fed positively.The internal program routine operates in four different possible casesas follows (see FIG. 7):

The uppermost signal diagram in FIG. 7 illustrates the rear edge of theactuating pulse for the "lifting" magnet 27 of the supply device, namelythe electromagnet is de-activated at the moment t1 and releases the arms7A out, 7B out, 7C out and 7D out, so that they are prepared for thenext operation, which produces a "trig signal". In the case 1, namely atthe moment t2, the arm 7A was moved outward into the "trig position" dueto a color change, since in the ring device a new yarn FA' was pickedup. In this case, the microprocessor FMP produces as programmed at themoment t2 an actuating signal and switches on the current to theelectromagnet 9A.

In case 2, the arm 7D out was moved with the old yarn FD' at the momentt3 into the "trig position". In this case, a color change in the ringdevice will not take place during the knitting machine rotation; rather,the needles continue to knit the old yarn FD'. At the moment t3, a"timer routine" starts in the microprocessor FMP, while themicroprocessor FMP is waiting for a possible "trig signal" for a newyarn, namely for the yarn FA. If during this "timer routine" (duration20 ms) such a "trig signal" does not occur, then the microprocessor FMPproduces in accordance with the program an actuating signal at themoment t3+20 ms, namely it switches on again the current to theelectromagnet 9D for the old yarn, so that same has priority and isagain fed positively.

In case 3, the arm 7D out is again moved at the moment t4 with the oldyarn FD into the "trig position". The "timer routine" is again startedin the microprocessor FMP. However, a short time later, at the momentt5, a "trig signal" is also received by the arm 7A out with the new yarnFA. This can only mean that the arm 7D out was moved at the moment t4erroneously into the "trig position", probably due to remaining tensionin the yarn FD', which cannot be the case with the new yarn FA'. Themicroprocessor FMP gives, as programmed, the trig signal for the newyarn priority and produces at the moment t5 an actuating signal for theelectromagnet 9A.

In case 4, no trig signal occurs whatsoever, either for the old yarn FDor for the new yarn FA, which means that an error exists, for example ayarn breakage. The microprocessor FMP in such supply device now producesand sends, as programmed, at the moment t6, determined by a third ordersignal III of the central control unit CU, a "GIVE STOP SIGNAL", a stopsignal on the STOP SIGNAL line back to the control unit CU, whichsubsequently again sends out a stop signal to a stop motion relay in theknitting machine for stopping the machine. At this moment, the currentto the error-indicating lamp 37 in the supply device which is inquestion here is switched on, so that the operator can easily determineat which knitting station the error occurred. The microprocessor CMP inthe central control unit CU also sends out a signal to its error-typeindicator, in the present case for example the code "1 1".

In all of the cases 1, 2 and 3, the microprocessor FMP in the supplydevice automatically switches on as programmed the stop function for therespective output yarn guiding arm only for the yarn which has given the"trig signal", namely in case 1 for the new yarn FA, in case 2 for theold yarn FD and in case 3 for the new yarn FA. The stop function, namelythe current feed to the contact cams 20A, 20B, 20C or 20D and thecontact tongues 24A, 24B, 24C or 24D, is programmed so that, in allsupply devices, it is switched on promptly after the "trig signal"occurs in the supply device.

In cases 1, 2 and 3, the microprocessor FMP in the supply deviceaccordingly does not answer the order signal 3 "GIVE STOP SIGNAL", sincea "trig signal" was received, which means that no error, as for examplea yarn breakage, existed.

On the other hand, the microprocessor FMP in every supply device isprogrammed for normal operation so that it sends back promptly a stopsignal on the "STOP SIGNAL" line to the central control unit if a threadbreakage in the just knitted yarn occurs, so that the knitting machineis stopped and an error-indicating lamp 37 and the display light up.Moreover, at the same time the current to all "engagement"electromagnets is switched off, so that the positive feeding of thethreads is stopped in order to prevent a temporary overfeeding of yarn.After repairing the error, for example a yarn breakage at one of thesupply devices, the operator switches on the restart switch T4 in thecentral control unit CU (see FIG. 5), which causes the microprocessorCMP in the control unit, as programmed, to switch off the current to thestop motion relay of the knitting machine and simultaneously to give theorder to the microprocessor FMP in the supply device in which the errorto switch off the error-indicating lamp 37 occurred, assuming that thestop contact which is in question here is again open. In this case, no"reset" of the program routine in the control unit takes place, but thesystem starts again as programmed by carrying out the operation whichwould have been next when the error occurred.

The operator can reset with the switch T1 the entire program in themicroprocessor CMP of the central control unit CU and themicroprocessors FMP in all supply devices, whereupon the entire programis again started automatically when the control unit receives the nextsynchronization pulse from the position sensor SYNC (see FIG. 5).

The switch T2 causes the central control unit CU to send out a specificcommon order to the microprocessors in all supply devices in order tokeep all electromagnets 9A, 9B, 9C and 9D without current so that noyarn is fed positively. The trig signal of the "trig contacts" 19A/21A,19B/21B, 19C/21C or 19D/21D is thereby, however, designed so that itconcerns, just like prior to the stop function, only the yarn which iscurrently being knitted. This mode of operation can be of considerableimportance during running of a new quality of material in the machine,namely before the speed of the tapes 6A, 6B, 6C and 6D (namely the yarnspeed) is adjusted correctly in relationship to the speed of theknitting machine.

Finally, the switch T3 effects in the control unit CU an additionalspecific order to the microprocessors FMP of all supply devices whichcauses the current to the one of the electromagnets 9A, 9B, 9C, 9D,which was operated by a "trig signal" to remain switched on, whereas thelifting-engagement electromagnets 27 are not actuated as during thenormal mode of operation during one machine rotation. This means thatthe respective yarn is constantly being fed positively. This specialfunction can be utilized when the ring knitting machine is to be usedfor knitting smooth fabric.

The invention is not limited to the above-described exemplary embodimentwhich is illustrated in the drawings, and a number of modifications arepossible which are within the scope of the invention.

The described exemplary embodiment is intended for a mechanicallycontrolled ring knitting machine, in which the ring devices arecontrolled in a mechanical manner from a central control unit.

However, the invention can be utilized particularly advantageously foran electronically controlled ring knitting machine, in which the ringdevices are controlled electrically through the central control unit.The information for the color change or the yarn change is accessibleelectrically in the central pattern program system of the knittingmachine itself. This means that, in this case, the necessity for atemporary lifting of the arms 7A out, 7B out, 7C out or 7D out into a"central" position and for the lowering of the arms by the new yarn doesnot exist. Since the temporary lowering of the output yarn guiding armsis not needed, a "lifting" electromagnet 27 is not needed. It is thenalso unnecessary to block the stop function for the output yarn guidingarm during the time during which the central control unit sends out anorder for ending the positive feed in the respective supply device.

In the electrically controlled ring knitting machine, the microprocessorCMP is programmed to send an order for the positive feed to therespective supply device and to simultaneously inform the microprocessorFMP in the supply device which of the four "engagement" electromagnets9A, 9B, 9C or 9D is to be operated.

Then, the stop function is switched on only for the yarn which wasordered by the central control unit CU for the positive feed.

When using the supply device group in a mechanically controlled ringknitting machine, the microprocessor CMP of the central control unit CUis, in dependence on the respective type of the ring knitting machine,designed or programmed right from the start with various informationtables in its internal memory (whereby the information tables can varyin dependence on the number of knitting stations of the machine, thespaces between the knitting stations and the like), so that theoperations which as a whole are to be carried out in all supply devices,the sequence in which such operations are to be carried out, and thepoints in time at which these operations must be carried out isestablished. The points in time at which these operations must becarried out are determined by establishing at which pulse in the pulsetrain from the pulse generator FREQ they must be started, whereby thesynchronization pulses which the microprocessor receives from theposition sensor SYNC are counted.

When using the subject matter of the invention in an electronicallycontrolled ring knitting machine, these information tables for themicroprocessor CMP in the central control unit CU do not need to be soextensive, since in this case the microprocessor CMP works "on-line"with the knitting machine pattern computer, namely through an interfacecircuit IC (indicated by dashes in FIG. 5), and therefore continuouslyreceives information from the pattern computer PC which informs it ofthe necessary color change data during each machine rotation.

All other functions are in this case substantially the same as in theearlier described exemplary embodiment, which is used in a mechanicallycontrolled ring machine.

We claim:
 1. A yarn supply device group, comprising a central controlunit, a plurality of yarn supply devices adapted to be attached to atextile machine, and a plurality of conductors which are connected toeach said yarn supply device and to said central control unit, whereineach said yarn supply device includes electrically actuable devices andan electronic switching arrangement which controls said electricallyactuable devices, each said switching arrangement including a memorywhich can be written and read and which is adapted to store a uniqueaddress sent to the yarn supply device by said central control unitthrough at least one of said conductors, and wherein said centralcontrol unit includes means for sending said unique addresses to saidmemories of said yarn supply devices when said textile machine isswitched on.
 2. The yarn supply device group according to claim 1,wherein said plurality of conductors includes a first conductor throughwhich said unique addresses are supplied to said yarn supply devices,said first conductor including a plurality of sections which each extendbetween a respective pair of said yarn supply devices so that said yarnsupply devices are connected in series by said first conductor, saidyarn supply devices being connected in parallel to each of the otherconductors of said plurality of conductors.
 3. The yarn supply devicegroup according to claim 2, wherein each said switching arrangementincludes a microprocessor.
 4. The yarn supply device group according toclaim 3, wherein each said switching arrangement includes manuallyoperable switch means for electrically disconnecting said microprocessorfrom said other conductors.
 5. The yarn supply device group according toclaim 3, wherein said microprocessor of each said yarn supply deviceincludes said memory thereof and also includes a read only memory havingtherein a fixed control program.
 6. The yarn supply device groupaccording to claim 1, wherein said central control unit includes amicroprocessor having an input to which is connected a control elementwhich generates a clock signal.
 7. The yarn supply device groupaccording to claim 6, wherein said microprocessor of said centralcontrol unit has further inputs, and including means for supplyingsignals to said further inputs which represent the operating positionand speed of the textile machine.
 8. The yarn supply device groupaccording to claim 6, wherein said microprocessor of said centralcontrol unit includes a memory which stores at least one fixed controlprogram.
 9. The yarn supply device group according to claim 1, whereineach said switching arrangement has means for detecting an error and fortransmitting a signal representing said error to said central controlunit through said plurality of conductors, and wherein said centralcontrol unit includes error indicator means for providing an indicationof the occurrence of the error.
 10. The yarn supply device groupaccording to claim 9, wherein each said yarn supply device includes amicroprocessor and an error-indicating device which can be controlled bysaid microprocessor.
 11. The yarn supply device group according to claim1, wherein each said switching arrangement is located within a housingof the associated yarn supply device.
 12. A yarn supply device group,comprising an annular carrier, a plurality of yarn supply devices whichare releasably fastened on said annular carrier and which each include aswitching arrangement having first connector means in the region of suchfastening and having a memory, a plurality of conductors which areelectrically connected to a plurality of second connector means whichare in turn releasably coupled to respective said first connector meansso as to electrically couple each said yarn supply device to saidplurality of conductors, and a central control device supported on saidannular carrier and electrically coupled to said plurality ofconductors, wherein said central control device includes means forsending a respective unique address through said plurality of conductorsto each of said switching arrangements in response to the application ofpower to the yarn supply device group, each said switching arrangementhaving means for storing in said memory thereof its unique address,wherein said plurality of conductors includes six wires which lieside-by-side and are each connected to each said second connector means,a first said wire being used to transmit said addresses to saidswitching arrangements and being a plurality of separate sections whichare each electrically coupled at one end to an input of a respectivesaid switching arrangment and at the opposite end to an output of adifferent said switching arrangement.
 13. A yarn supply device group fora textile machine, comprising a control unit, a plurality of yarn supplydevices which each include an electronic circuit having a memory whichcan be written and read, and bus cable means connected to said controlunit and to each of said yarn supply devices and having a plurality ofconductors; wherein said contol unit includes means for supplying toeach said supply device through said bus cable means a unique address inresponse to the application of power to the textile machine; whereineach said electronic circuit includes means for storing in said memorythereof the unique address supplied thereto; wherein said control unitincludes means for sending command signals through said bus cable meansduring normal operation of the textile machine, each said command signalincluding a portion which is an address signal and a portion which is anorder signal; and wherein each said electronic circuit includes meansfor comparing said address signal of each said command signal to theunique address stored in its memory and for carrying out a predeterminedaction in response to the order signal of each said command signal inwhich the address signal corresponds to the unique address stored insaid memory.
 14. The yarn supply device group according to claim 13,wherein said bus cable means includes a plurality of identical firstconnector means provided at spaced locations, and wherein each said yarnsupply device includes second connector means releasably coupled to arespective one of said first connector means, said second connectormeans being identical to each other.
 15. The yarn supply device groupaccording to claim 13, wherein said bus cable means includes a currentwire for supplying power to said electronic circuit in each said yarnsupply device, a reset wire for selectively resetting said electroniccircuit in each said yarn supply device, a stopsignal wire through whicheach said electronic circuit can send signals to said control unit, anda clock wire and data wire which respectively carry a clock signal anddata signals from said control unit to each said electronic circuit, andwherein said bus cable means includes a plurality of relay wiresegments, one of said relay wire segments connecting an output of saidcontrol unit to an input of the control circuit in a respective one ofsaid yarn supply devices, and the rest of said relay wire segments eachconnecting an output of the control circuit of a respective said yarnsupply device to an input of the control circuit of a different saidyarn supply device.